Spinner Nathan Lyon starred with a match haul of nine wickets as Australia wrapped up the opening Test on Friday with a crushing victory over Sri Lanka before lunch on the third day.

The hosts were bundled out for 113 in their second innings allowing the Australians to seal a 10-wicket victory in their first over back at the crease in Galle.

Lyon, whose five-for helped bowl out Sri Lanka for 212 in the first innings, and fellow spinner Travis Head took four wickets each to send the hosts packing before the morning was over.

It was a huge victory for Australia, who suffered a 3-0 whitewash in Sri Lanka on their last tour in 2016.

Sri Lanka suffered a blow before play began when Angelo Mathews was ruled out due to Covid-19, with Oshada Fernando named his replacement.

Skipper Dimuth Karunaratne started strong, smashing four boundaries in the 17-run first over of the innings off Mitchell Starc.

But the tables soon turned when Lyon and fellow spinner Mitchell Swepson took charge.

Lyon got skipper Karunaratne caught behind for 23 after just 20 balls while Swepson trapped Pathum Nissanka lbw for 14.

The leg-spinner then got Oshada caught out in the 12th over as Sri Lanka slipped to 63-4.

Wickets kept tumbling with Sri Lanka's batsmen desperately trying to hit their way out of trouble.

Head, a left-handed batsman and an occasional off-spinner, struck twice in his first over to claim Dinesh Chandimal and Dhananjaya de Silva.

Swashbuckling opener David Warner brought an easy finish to formalities, hitting a four and a six off Ramesh Mendis to bring up the win in four balls.

Earlier in the day, fast bowler Asitha Fernando took Australia's last two first-innings wickets with the tourists adding eight to their overnight 313, for a commanding lead of 109.

Opener Usman Khawaja (71) and Cameron Green (77) stood out in Australia's first innings effort.

Ramesh Mendis took four wickets while debutant Jeffrey Vandersay took two.

The third day started early after abysmal weather shortened play on Thursday, with strong winds collapsing a spectator stand.

The second and final Test begins July 8 at the same venue.